“Unwinds” the rotational axis machine position value.
It divides the position value by 360 and uses the remainder of division (if any) as a new machine position value of rotational axis.
If you want to run a G-code program that uses rotational axis and its current position value is 1350°, then the unwind will set it to 270°.
You can select which axis you want to unwind.
This program feature is scriptable.
For more info regarding Scripts, please read chapters Scripts.